The Value of Radiotherapy in Patients With Resectable Stage IIIA Non-Small-Cell Lung Cancer in the Era of Individualized Treatment: A Population-Based Analysis

Introduction: No consensus has been achieved on the benefit of radiotherapy for resected stage IIIA NSCLC patients. The division of stage IIIA has changed significantly in 2017. This study aims to explore the effects of radiotherapy on the survival of patients with resectable stage IIIA NSCLC in the new era.

Patients and methods: Patients diagnosed with NSCLC between 2010 and 2018 were identified in the 8th edition TNM classification from the Surveillance, Epidemiology, and End Results database. A nomogram was developed by integrating all independent predictors for lung cancer-specific survival (LCSS). The Propensity Score Matching (PSM) and subgroup analysis were applied to mitigate potential bias. Survival analyses were conducted using the Kaplan Meier curves and Cox proportional hazards regression.

Results: A total of 2632 stage IIIA NSCLC patients were enrolled. The C-index of the nomogram for the prediction of LCSS was 0.636 (95% CI, 0.616-0.656). In the group of patients with N2 stage who featured more than 5 positive regional lymph nodes, compared with non-PORT, PORT did prolong postoperative survival time (50 vs. 31 months; P= .005). N2 patients with visceral pleural invasion (VPI), older (age >65), or had a larger tumor (size >3 cm) could also benefit from adjuvant radiotherapy.

Conclusion: Treatment protocol for stage IIIA NSCLC patients should be individualized. Based on our findings, N2 patients with more than 5 positive regional lymph nodes, VPI, larger tumor size (greater than 3 cm), and older (age above 65) could benefit from adjuvant radiotherapy. Further well-designed randomized trials are warranted.